HealthWatch: Deep-vein thrombosis

How do you avoid getting sicker while admitted to hospital? Most people might think that cleanliness and avoiding superbugs are the keys to surviving a hospital stay but a more important and largely preventable condition relates to the development of blood clots. The trouble is that some hospitals may be failing the grade in this regard. This week’s HealthWatch examines research that sheds light on the problem and looks at what patients and their families can do to help.

Although bedrest is an inevitable part of the recovery from surgery or illnesses such as pneumonia, staying in bed for more than just a few days may also lead to a complication with potentially deadly repercussions. Under these circumstances, patients can develop a blood clot in one of their legs known as a deep-vein thrombosis or a DVT, also commonly called phlebitis.

When a deep-vein thrombosis occurs in one of the large, deep veins of the calf or thigh, it partially or completely blocks blood returning to the heart. While the condition usually occurs in people over age 60, it can happen to anyone. People often associate this disease with prolonged travel either in a plane’s economy class or in cars and trains and although this is true, hospital-related thrombosis is many times more common. In particular, patients undergoing orthopedic and abdominal surgeries are at greatest risk. However, others at risk include those who suffer from heart failure, cancer and infections as well as those who have sustained a leg injury or stroke; all risks that can be compounded by a prolonged hospitalization.

Some patients with deep-vein thrombosis have pain or swelling in one leg while others have no symptoms. The most serious consequence of deep-vein thrombosis is a pulmonary embolism, where the blood clot travels to the lungs. There, it can cause chest pain or shortness of breath and even trigger a cardiac arrest. Autopsy studies have shown that some of the sudden deaths that occur in the post-operative period or during hospitalization for serious medical illness are due to a pulmonary embolism, but these were often not suspected as such by the treating team. When a thrombosis is detected by vein or lung imaging tests, the treatment usually consists of taking months of a blood-thinning medication which, while effective in treating the blood clot, in turn carries an increased risk of bleeding.

Deep-vein thrombosis affects thousands of Canadians each year. Although not highly publicized, complications from deep-vein-thromboses contribute to more deaths each year than AIDS and breast cancer combined. Remarkably, prevention of this common and dangerous problem in the hospital setting is effective, easy, safe and inexpensive and involves, among other measures, injections of small doses of blood thinners just under the skin of the abdomen for a key period around the time of admission or surgery.

The study

Venous thromboembolism risk and prophylaxis in the acute hospital care setting (titled Epidemiologic International Day for the Evaluation of Patients at Risk for Venous Thromboembolism in the Acute Hospital Care Setting or ENDORSE): a multinational cross-sectional study. Cohen AT, Tapson VF, Bergmann JF, et al, for the ENDORSE Investigators, The Lancet, Feb. 2.

What question did this study attempt to answer?

The study was designed to answer two questions. First, how significant is the risk for deep-vein thrombosis in acute hospital care facilities? And second, how well are these hospitals doing in providing effective preventive measures?

Researchers collected records from 358 hospitals in 32 countries, making up a population of more than 68,000 patients studied between August 2006 and January 2007.

The researchers looked at two groups of patients: those hospitalized for non-surgical reasons – the medical group – and those admitted for surgery. The study was sponsored by the makers of one of the blood thinning medications.

What preventive measures were used for patients at risk?

In the at-risk population, blood thinners – mainly the gold standard, heparin – were the main treatments used. Other non-pharmaceutical measures such as foot pumps and compression stockings were used more commonly among the surgical patients.

What were the study’s findings?

The report shows clearly that preventive measures for deep-vein thrombosis are severely underused. Just about half of the medical and surgical patients were assessed as being at risk for deep-vein thrombosis, and yet roughly only half of these received preventive care. Interestingly, the provision of care varied, depending on the type of problem that led to hospitalization: most patients in hospital for hip or knee replacement surgery received it while less than half of hospitalized cancer or heart-failure patients received it. Although there were no Canadian sites in this report, a 2006 study of 29 hospitals across this country revealed similar if not worse performance for preventing deep-vein thrombosis.

Why aren’t hospitals using these proven strategies for preventing thrombosis?

One of the reasons cited for the lack of prevention is disagreement or lack of knowledge among physicians about the actual risk of developing deep-vein thrombosis. A second one is that current guidelines for the prevention of deep-vein thrombosis risk do not address such conditions as heart failure and infections, and consensus guidelines are being revisited as a result.

Another dimension to bear in mind is that the healthcare providers are often slow to adopt change and that raising awareness and instituting preventive measures on such a wide scale requires that systems be put in place to help remind treating doctors of their importance.

Is there anything that patients and their loved ones can do to reduce the risk of developing this complication?

Heightened awareness of the risks, and knowing what can be done to prevent in-hospital deep-vein thrombosis can empower patients and their caregivers to try to ensure that certain practices are followed – or at the very least, equip them to ask the right questions of their healthcare providers.

Given that in-hospital deep-vein thrombosis and pulmonary embolism are largely preventable, it behooves us as users of the healthcare system, and advocates for our loved ones, to team up with doctors, nurses and other healthcare professionals in an effort to reduce their occurrence and, at the same time, the numbers of tragic deaths arising from their complications.

March is deep-vein thrombosis awareness month as part of an effort across North America to raise levels of education and awareness of the condition and ways in which it can be prevented.

The authors wish to thank Susan Kahn, a thrombosis specialist at the SMBD Jewish General Hospital, as well as Marc Afilalo, chief of the SMBD Jewish General Hospital Emergency Department, and Jessica Emed, clinical nurse specialist in thrombosis, for their input into this column.

The material provided in HealthWatch is designed for general educational purposes only and does not pertain to individual cases. The information included should not replace necessary medical consultations with your own doctor or medical professional.

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